<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .box1 {
            background: red;
        }
        .box2 {
            background: yellow;
        }
        .box3 {
            background-color: blue;
            float: left;
            width: 100px;
            height: 100px;
        }
        
    </style>
</head>
<body>
    <div class="box1">
        <ul>
            <li>ddddd1</li>
            <li>ddddd2</li>
            <li>ddddd3</li>
        </ul>
    </div>
    <div class="box2">
        <ul>
            <li>cccc1</li>
            <li>cccc2</li>
            <li>cccc3</li>
        </ul>
    </div>

    <div class="box3">
        <div class="box4">

        </div>
    </div>
</body>
</html>